Both are touring the energy-rich region and landing days apart in the wealthy United Arab Emirates.
Mr. Cheney arrived in the Emirates capital Abu Dhabi yesterday. Mr. Ahmadinejad, who is expected to be greeted with great fanfare as the first Iranian head of state to visit, is expected Sunday, after a visit to Oman.
The Gulf Arab countries are longtime U.S. allies, but the Bush administration’s war in Iraq has triggered a strong effort by Iran to woo them out of the American camp.
But for its part, Iran has many across the region scared over its insistence on developing a nuclear program.
Washington has countered Iran’s growing assertiveness in the region with a flurry of diplomatic visits and a second U.S. aircraft carrier steaming off Iran’s coast.
Leaders in the Gulf, now in the midst of a lucrative economic boom, fear being sandwiched in a disastrous U.S.-Iran war. Neither Mr. Cheney nor Mr. Ahmadinejad is expected to win big concessions from the Gulf Arabs.
"We have a deep mistrust of both sides," said Mustafa Alani of the Dubai-based Gulf Research Center. "Each is trying to defend his corner on major issues in the region. But neither is likely to accomplish very much."
Mr. Cheney, who is also traveling to Saudi Arabia, Egypt and Jordan, is expected to press Emirates President Sheik Khalifa bin Zayed Al Nahyan for support for U.S. efforts in Iraq, and to shut down Iranian companies here that U.S. officials think are backing the country’s nuclear development. About 500,000 Iranians live in the Emirates, just across the Persian Gulf from Iran.
"We have a common interest with the U.S. in preventing Iran from becoming a nuclear power and intervening in Iraq and Lebanon," Mr. Alani said. "But the problem is that we have a huge mistrust of the U.S. and cannot publicly support its position."
Mr. Ahmadinejad wants the Emirates, Oman and the other Gulf Arab countries to drop their military alliances with Washington and join Iran in a regional effort to maintain stability in the energy-rich Gulf. Washington maintains 40,000 troops on land bases in Gulf countries outside Iraq and currently has 20,000 sailors and Marines in the region.